Elementary Statistics Question And Answer

Identify whether the statement describes inferential statistics or descriptive statistics. There is a relationship between smoking cigarettes and getting emphysema. - correct answer inferential statistics From past figures, it is predicted that 19% of the registered voters in California will vote in the June primary. - correct answer descriptive statistics Determine whether the data are qualitative or quantitative. the number of seats in a movie theater - correct answer quantitative Identify the data set's level of measurement. hair color of women on a high school tennis team - correct answer nominal Identify the data set's level of measurement. number of milligrams of tar in 85 cigarettes - correct answer ratio Identify the data set's level of measurement. the ratings of a movie ranging from "poor" to "good" to "excellent" - correct answer ordinal Identify the data set's level of measurement. the final grades (A, B, C, D, and F) for students in a statistics class - correct answer ordinal Identify the data set's level of measurement. the nationalities listed in a recent survey (for example, Asian, European, or Hispanic). - correct answer nominal Identify the data set's level of measurement. manuscripts rated "acceptable" or "unacceptable" - correct answer ordinal Identify the data set's level of measurement. the lengths (in minutes) of the top ten movies with respect to ticket sales in 2007 - correct answer ratio Decide which method of data collection you would use to collect data for the study. Specify either observational study, experiment, simulation, or survey. A study where a drug was given to 23 patients and a placebo to another group of 23 patients to determine if the drug has an effect on a patient's illness - correct answer experiment Decide which method of data collection you would use to collect data for the study. Specify either observational study, experiment, simulation, or survey. A study where you would like to determine the chance getting three girls in a family of three children - correct answer simulation Identify the sampling technique used. Every fifth person boarding a plane is searched thoroughly. - correct answer systematic Identify the sampling technique used. A researcher for an airline interviews all of the passengers on five randomly selected flights. - correct answer cluster Identify the sampling technique used. A lobbyist for a major airspace firm assigns a number to each legislator and then uses a computer to randomly generate ten numbers. The lobbyist contacts the legislators corresponding to these numbers. - correct answer random Identify the sampling technique used. A market researcher randomly selects 200 drivers under 55 years of age and 200 drivers over 55 years of age. - correct answer stratified Identify the sampling technique used. A researcher randomly selected 25 of the nation's middle schools and interviewed all of the teachers at each school. - correct answer cluster Solve the problem. The average age of the students in a statistics class is 22 years. Does this statement describe: - correct answer descriptive statistics? Solve the problem. Based on previous clients, a marriage counselor concludes that the majority of marriages that begin with cohabitation before marriage will result in divorce. Does this statement describe inferential statistics or descriptive statistics? - correct answer inferential statistics Solve the problem. Classify the number of seats in a movie theater as qualitative data or quantitative data. - correct answer quantitative data Solve the problem. Identify the level of measurement for data that are the temperature of 90 refrigerators. - correct answer interval Solve the problem. Identify the level of measurement for data that are the number of milligrams of tar in 79 cigarettes. - correct answer ratio Solve the problem. Identify the level of measurement for data that are the ratings of a movie ranging from poor to good to excellent. - correct answer ordinal Solve the problem. Identify the level of measurement for data that are the nationalities listed in a recent survey (for example, Asian, European, or Hispanic). - correct answer nominal Solve the problem. The numbers of touchdowns scored by a major university in five randomly selected games are given below. Identify the level of measurement. 1 5 4 5 5 - correct answer ratio Solve the problem. What method of data collection would you use to collect data for a study where a political pollster wishes to determine if his candidate is leading in the polls? - correct answer use sampling Solve the problem. At a local community college, five statistics classes are randomly selected and all of the students from each class are interviewed. What sampling technique is used? - correct answer cluster Solve the problem. A community college student interviews everyone in a statistics class to determine who owns a car. What sampling technique is used? - correct answer convenience Solve the problem. A lobbyist for a major airspace firm assigns a number to each legislator and then uses a computer to randomly generate ten numbers. The lobbyist contacts the legislators corresponding to these numbers. What sampling technique was used? - correct answer random Solve the problem. A market researcher randomly selects 200 drivers under 35 years of age and 100 drivers over 35 years of age. What sampling technique was used? - correct answer stratified Solve the problem. The names of 70 contestants are written on 70 cards. The cards are placed in a bag, and three names are picked from the bag. What sampling technique was used? - correct answer random Solve the problem. What method of data collection would you use to collect data for a study where you would like to determine the chance getting three girls in a family of three children? - correct answer use a simulation Use the given frequency distribution to find the (a) class width. (b) class midpoints of the first class. (c) class boundaries of the first class. Phone Calls (per day) (a) 3 (b) 9.5 (c) 7.5-11.5 (a) 3 (b) 10.5 (c) 8-11 (a) 4 (b) 10.5 (c) 8-11 (a) 4 (b) 9.5 (c) 7.5-11.5 - correct answer a) 4 (b) 9.5 (c) 7.5-11.5 Provide an appropriate response. Use the ogive below to approximate the cumulative frequency for 24 hours. Student Answer: 75 27 17 63 - correct answer 63 For the given data , construct a frequency distribution and frequency histogram of the data using five classes. Describe the shape of the histogram as symmetric, uniform, skewed left, or skewed right. Data set: California Pick Three Lottery 8 6 7 6 0 9 1 7 8 4 1 5 7 5 9 7 5 3 9 9 8 8 3 9 8 8 9 0 2 7 skewed right symmetric uniform skewed left - correct answer Skewed Left Provide an appropriate response. Use the histogram below to approximate the mode heart rate of adults in the gym. a) 70 b) 2 c) 55 d) 42 - correct answer 70 Provide an appropriate response. The top 14 speeds, in miles per hour, for Pro-Stock drag racing over the past two decades are listed below. Find the median speed. 118.1 202.2 190.1 201.4 191.3 201.4 192.2 201.2 193.2 201.2 194.5 199.2 196.0 196.2 195.8 201.2 196.7 196.1 - correct answer 196.1 Provide an appropriate response. The scores of the top ten finishers in a recent golf tournament are listed below. Find the median score. - correct answer 72 Provide an appropriate response. Grade points are assigned as follows: A = 4, B = 3, C = 2, D = 1, and F = O. Grades are weighted according to credit hours. If a student receives an A in a four-unit class, a D in a two-unit class, a B in a three-unit class and a C in a three-unit class, what is the student's grade point average? - correct answer 2.75 Provide an appropriate response. The lengths of phone calls from one household (in minutes) were 2, 4, 6, 7, and 8 minutes. Find the midrange for this data. 2 minutes 5 minutes 6 minutes 10 minutes - correct answer 5 min Provide an appropriate response. Find the range of the data set represented by the graph. 6 20 5 17 - correct answer 6 Provide an appropriate response. Find the sample standard deviation. 2 6 15 9 11 22 1 4 8 19 - correct answer 7.1 Provide an appropriate response. The mean score of a placement exam for entrance into a math class is 80, with a standard deviation of 10. Use the Empirical Rule to find the percentage of scores that lie between 60 and 80. (Assume the data set has a bell-shaped distribution.) 95% 34% 47.5% 68% - correct answer 47.5% Provide an appropriate response. The mean score of a competency test is 77, with a standard deviation of 4. Use the Empirical Rule to find the percentage of scores between 69 and 85. (Assume the data set has a bell-shaped distribution.) 95% 68% 50% 99.7% - correct answer 95% Provide an appropriate response. The mean SAT verbal score is 478, with a standard deviation of 98. Use the Empirical Rule to determine what percent of the scores lie between 380 and 478. (Assume the data set has a bell-shaped distribution.) 34% 47.5% 68% 49.9% - correct answer 34% Use the grouped data formulas to find the indicated mean or standard deviation. The manager of a bank recorded the amount of time a random sample of customers spent waiting in line during peak business hours one Monday. The frequency distribution below summarizes the results. Approximate the sample mean. Round your answer to one decimal place. 9.0 13.5 9.2 7.7 - correct answer 9.2 Use the grouped data formulas to find the indicated mean or standard deviation. A random sample of 30 high school students is selected. Each student is asked how many hours he or she spent on the Internet during the previous week. The results are shown in the histogram. Estimate the sample mean. 8.1 8.3 7.9 7.7 - correct answer 7.9 Provide an appropriate response. In a random sample, 10 students were asked to compute the distance they travel one way to school to the nearest tenth of a mile. The data is listed below. a) If a constant value k is added to each value, how will the standard deviation be affected? b) If each value is multiplied by a constant k, how will the standard deviation be affected? 1.1 5.2 3.6 5.0 4.8 1.8 2.2 5.2 1.5 0.8 - correct answer The standard deviation will not be affected. The cholesterol levels (in milligrams per deciliter) of 30 adults are listed below. Find Q1. - correct answer 180 Provide an appropriate response. Find the z-score for the value 55, when the mean is 58 and the standard deviation is 3. z = 0.90 z = -0.90 z = -1.00 z = -1.33 - correct answer z= -1.00 Provide an appropriate response. The test scores of 30 students are listed below. Find P30. 55 56 63 65 67 67 56 90 63 - correct answer 63 Provide an appropriate response. A teacher gives a 20-point quiz to 10 students. The scores are listed below. What percentile corresponds to the score of 12? 13 12 25 40 - correct answer 40 Solve the problem. The scores of the top ten finishers in a recent LPGA Valley of the Stars Tournament are listed below. (Source: Los Angeles Times) 68 72 72 Find the mode score. 67 73 72 76 - correct answer 72 Solve the problem. The top 14 speeds, in miles per hour, for Pro-Stock drag racing over the past two decades are listed below. Find the median speed. 181.1 202.2 190.1 201.4 191.3 201.4 192.2 201.2 193.2 201.2 194.5 199.2 196.0 196.2 201.2 192.2 196.7 196.1 - correct answer 196.1 Solve the problem. For the following data set, approximate the sample standard deviation of phone calls per day. 8-11 18 12-15 23 16-19 38 20-23 47 24-27 32 2.9 18.8 3.2 5.1 - correct answer 5.1 Solve the problem. Find the range of the data set represented by the graph. 20 15 10 5 0 1 2 3 4 5 6 7 a) 20 b) 17 c) 6 d) 5 - correct answer c) 6 Solve the problem. Find the z-score for the value 70, when the mean is 76 and the standard deviation is 2. z= -.89 z= -3.00 z= .89 z= -3.50 - correct answer z= -3.00 Solve the problem. The average IQ of students in a particular calculus class is 110, with a standard deviation of 5. The distribution is roughly bell-shaped. Use the Empirical Rule to find the percentage of students with an IQ above 120. 2.5% 11.15% 15.85% 13.5% - correct answer 2.5% Solve the problem. The ages of 10 grooms at their first marriage are listed below. Find the midquartile. 35.1 24.3 46.6 41.6 32.9 26.8 39.8 21.5 45.7 33.9 43.7 34.5 34.1 34.2 - correct answer 34.2 Solve the problem. For the mathematics part of the SAT the mean is 514 with a standard deviation of 113, and for the mathematics part of the ACT the mean is 20.6 with a standard deviation of 5.1. Bob scores a 660 on the SAT and a 27 on the ACT. Use z-scores to determine on which test he performed better. ACT SAT - correct answer SAT Solve the problem. For the following data, approximate the mean number of phone calls per day. 8-11 31 12-15 34 16-19 28 20-23 30 24-27 6 16 15 14 26 17 - correct answer 16 Solve the problem. For the following data, approximate the mean number of phone calls per day. 8-11 48